WHILE EXITING OF A HIGHWAY AND TRAVELING 25 MPH MY BRAKES COMPLETELY FAILED. I PUSHED THE PEDAL TO THE FLOOR SEVERAL TIMES BUT IT DID NOT SLOW THE TRUCK. AS A RESULT I REAR ENDED A VEHICLE IN FRONT OF ME. I HAD NOW WARNING OR CHECK LIGHT FOR THE BRAKES PREVIOUS OR SINCE. UPON INSPECTION I DISCOVERED CORRODED AND LEAKING BRAKE LINES IN THE MIDDLE SECTION OF MY TRUCK.